Co-delivery of VEGF and amoxicillin using LP-coated co-axial electrospun fibres for the potential treatment of diabetic wounds

Diabetic complications present throughout a wide range of body tissues, however one of the most widely recognised complications remains to be chronic diabetic wounds. Current treatment options largely rely on standard wound treatment routines which provide no promotion of wound healing mechanisms at different physiological stages of repair. Recently materials produced using novel additive manufacturing techniques have been receiving attention for applications in wound care and tissue repair. Additive manufacturing techniques have recently been used in the interest of targeted drug delivery and production of novel materials resembling characteristics of native tissues. The potential to exploit these highly tailorable manufacturing techniques for the design of novel wound care remedies is highly desirable. In the present study two additive manufacturing techniques are combined to produce a scaffold for the treatment of diabetic wounds. The combination of microfluidic manufacturing of an antimicrobial liposome (LP) formulation and a coaxial electrospinning method incorporating both antimicrobial and proangiogenic factors allowed dual delivery of therapeutics to target both infection and lack of vascularisation at wound sites. The coaxial fibres comprised of a polyvinyl alcohol (PVA) core containing vascular endothelial growth factor (VEGF) and a poly (l-lactide-co-ε-caprolactone) (PLCL) shell blended with amoxicillin (Amox). Additionally, a liposomal formulation was produced to incorporate Amox and adhered to the surface of fibres loaded with Amox and VEGF. The liposomal loading provided the potential to deliver a much higher, more clinically relevant dose of Amox without detrimentally changing the mechanical properties of the material. The growth factor release was sustained up to 7-days in vitro. The therapeutic effect of the antibiotic loading was analysed using a disk diffusion method with a significant increase in zone diameter following LP adhesion, proving the full scaffold system had improved efficacy against both Gram-positive and Gram-negative strains. Additionally, the dual-loaded scaffolds show enhanced potential for supporting vascular growth in vitro, as demonstrated via a viability assay and tubule formation studies. Results showed a significant increase in the average total number of tubes from 10 in control samples to 77 in samples fully-loaded with Amox and VEGF.

Assessing the Efficacy of Active Learning to Support Student Performance Across Undergraduate Programmes in Biomedical Science

Introduction: Active learning is a useful tool to enhance student engagement and support learning in diverse educational situations. We aimed to assess the efficacy of an active learning approach within a large interprofessional first year Medical Cell Biology module taken by six healthcare programmes across the School of Biomedical Sciences at Ulster University, United Kingdom. Materials and methods: An active learning approach was developed for weekly formative assessment using Smartwork to design a weekly interactive multiple-choice quiz to reinforce key concepts specifically for each lecture. We tracked and assessed student performance in the module overall and in each element of course work and exam for 2 years prior to and following the introduction of an active learning strategy to engage and support learning for students from all academic backgrounds and abilities. Results: Full engagement with active learning was significantly associated with an increased overall module performance as well as a significantly increased performance in each element of class test (No engagement vs. Full engagement, p < 0.001), exam (No Engagement vs. Full engagement, p < 0.05) and coursework (No engagement vs. Full engagement, p < 0.001) within this overall total (No Engagement vs. Full engagement, p < 0.01). Partial engagement with active learning was associated significantly improved class test (No engagement vs. partially engaged, p < 0.001) and coursework (No engagement vs. partially engaged, p < 0.05) performance. While a trend toward increased performance in exam and overall module mark was observed, these were not significant. Discussion: Active learning is a useful tool to support student learning across a range of healthcare programmes taken by students with differing backgrounds and academic abilities in an interprofessional and widening participation setting. Student engagement in active learning was highlighted as a key contributory factor to enhanced student performance in all aspects of assessment.

Liposomal encapsulation of amoxicillin via microfluidics with subsequent investigation of the significance of PEGylated therapeutics

With an increasing concern of global antimicrobial resistance, the efforts to improve the formulation of a narrowing library of therapeutic antibiotics must be confronted. The liposomal encapsulation of antibiotics using a novel and sustainable microfluidic method has been employed in this study to address this pressing issue, via a targeted, lower-dose medical approach. The study focusses upon microfluidic parameter optimisation, formulation stability, cytotoxicity, and future applications. Particle sizes of circa. 130 nm, with viable short-term (28-day) physical stability were obtained, using two different non-cytotoxic liposomal formulations, both of which displayed suitable antibacterial efficacy. The microfluidic method allowed for high encapsulation efficiencies (≈77 %) and the subsequent in vitro release profile suggested high limits of antibiotic dissociation from the nanovessels, achieving 90% release within 72 h. In addition to the experimental data, the growing use of poly(ethylene) glycol (PEG) within lipid-based formulations is discussed in relation to anti-PEG antibodies, highlighting the key pharmacological differences between PEGylated and non-PEGylated formulations and their respective advantages and drawbacks. It's surmised that in the case of the formulations used in this study, the addition of PEG upon the liposomal membrane would still be a beneficial feature to possess owing to beneficial features such as stability, antibiotic efficacy and the capacity to further modify the liposomal membrane.

Combining microfluidics and coaxial 3D-bioprinting for the manufacturing of diabetic wound healing dressings

Diabetic foot ulcers (DFUs) are a crucial complication of diabetes, as in a diabetic wound, each step of the physiological healing process is affected. This entails a more easily infectable wound, and delayed tissue regeneration due to the inflammation that occurs, leading to a drastic decrease in the overall patient's quality of life. As a strategy to manage DFUs, skin alternatives and wound dressings are currently receiving a lot of attention as they keep the wound environment "under control", while providing bioactive compounds that help to manage infection and inflammation and promote tissue repair. This has been made possible thanks to the advent of emerging technologies such as 3D Bioprinting to produce skin resembling constructs or microfluidics (MFs) that allows the manufacture of nanoparticles (NPs) that act as drug carriers, in a prompt and less expensive way. In the present proof-of-concept study, the possibility of combining two novel and appealing techniques in the manufacturing of wound dressings has been demonstrated for first time. The novelty of this work consists in the combination of liposomes (LPs) encapsulating the active pharmaceutical ingredient (API) into a hydrogel that is further printed into a three-dimensional scaffold for wound dressing; to the knowledge of the authors this has never been done before. A grid-shaped scaffold has been produced through the coaxial 3D bioprinting technique which has allowed to combine, in one single filament, two different bioinks. The inner core of the filament is a nanocomposite hydrogel consisting of hydroxyethyl cellulose (HEC) and PEGylated LPs encapsulated with thyme oil (TO) manufactured via MFs for the first time. The outer shell of the filament, instead, is represented by a hybrid hydrogel composed of sodium alginate/cellulose nanocrystals (SA/CNC) and enriched with free TO. This provides a combination of two different release ratios of the API, a bulk release for the first 24 h thanks to the free TO in the shell of the filament and a sustained release for up to 10 days provided from the API inside the LPs. Confocal Microscopy verified the actual presence of the LPs inside the scaffold after printing and evaluation using the zone of inhibition test proved the antibacterial activity of the manufactured scaffolds against both Gram-positive and Gram-negative bacteria.

Production of photoionized plasmas in the laboratory with x-ray line radiation

In this paper we report the experimental implementation of a theoretically proposed technique for creating a photoionized plasma in the laboratory using x-ray line radiation. Using a Sn laser plasma to irradiate an Ar gas target, the photoionization parameter, ξ=4πF/N_{e}, reached values of order 50ergcms^{-1}, where F is the radiation flux in ergcm^{-2}s^{-1}. The significance of this is that this technique allows us to mimic effective spectral radiation temperatures in excess of 1 keV. We show that our plasma starts to be collisionally dominated before the peak of the x-ray drive. However, the technique is extendable to higher-energy laser systems to create plasmas with parameters relevant to benchmarking codes used to model astrophysical objects.

Verification of an alternative sludge treatment process for pathogen reduction at two wastewater treatment plants in Victoria, Australia

At South East Water wastewater treatment plants (WwTPs) in Victoria, Australia, biosolids are stockpiled for three years in compliance with the State guidelines to achieve the highest pathogen reduction grade (T1), suitable for unrestricted use in agriculture and landscaping. However, extended stockpiling is costly, may increase odour nuisance and greenhouse gas emissions, and reduces the fertiliser value of the biosolids. A verification programme of sampling and analysis for enteric pathogens was conducted at two WwTPs where sludge is treated by aerobic and anaerobic digestion, air drying (in drying pans or solar drying sheds) and stockpiling, to enumerate and, if present, monitor the decay of a range of enteric pathogens and parasites. The sludge treatment processes at both WwTPs achieved T1 grade biosolids with respect to prescribed pathogenic bacterial numbers (<1 Salmonella spp. 50 g^-1 dry solids (DS) and <100 Escherichia coli g^-1 DS) and >3 log₁₀ enteric virus reduction after a storage period of one year. No Ascaris eggs were detected in the influent to the WwTPs, confirming previous studies that the presence of helminth infections in Victoria is extremely low and that Ascaris is not applicable as a control criterion for the microbiological quality of biosolids in the region.

Outcomes of Sacral Nerve Stimulation For Faecal Incontinence in Northern Ireland

BACKGROUND

Sacral nerve root stimulation (SNS) is an effective and developing therapy for faecal incontinence, a debilitating condition that can result in social and personal incapacitation.

OBJECTIVES

The objectives of this study are to assess the morbidity of the procedure, improvement in the incontinence scores and Quality of Life (QoL) following SNS.

MATERIALS AND METHODS

Patients were identified from the Northern Ireland regional SNS service from 2006 to 2012. Numbers of patients who had temporary placement and permanent placement were collated. Pre and postoperative assessment of severity of incontinence and QoL was performed using Cleveland Clinic Incontinence Score (CCIS) and Short Form-36 (SF-36) respectively. Statistical analysis was undertaken using Wilcoxon signed rank test. Morbidity was assessed by retrospective review of patient records.

RESULTS

Seventy-five patients were considered for trial of a temporary SNS. Sixty-one proceeded to insertion of a temporary SNS and, of these, 40 elected to have a permanent SNS. There was a significant reduction in the pre-SNS and post-SNS Cleveland Clinic Incontinence Scores from median of 14 to 9 respectively (p=0.008). There was a significant improvement in Role Physical (p=0.017), General Health (p=0.02), Vitality (p=0.043), Social Functioning (p=0.004), Role Emotional (p=0.007), Mental Health (p=0.013) and Mental Health Summary (p=0.003). However, this is not reflected in the bodily pain and physical functional domains.

CONCLUSION

Permanent sacral nerve stimulation is effective and results in significant improvement of faecal incontinence scores and quality of life.

Sedation for gastroscopy: Is it an adequately understood and informed choice?

INTRODUCTION

Sedation uptake rates for oesophagogastroduodenoscopy (OGD) vary greatly. Issues concerning adequate information and consent have been raised. Additionally, patient comprehension of sedation options is inconsistent.

METHODS

A closed ended questionnaire was created and delivered to assess patient understanding regarding sedation prior to OGD. The questionnaire was based on British Society of Gastroenterology guidelines.

RESULTS

One hundred and eleven patients were recruited. 90 % of the sedated and 73 % of the unsedated patients were satisfied with their respective decisions (OR 0.283, *p = 0.01). 65 % were unaware of basic differences between conscious sedation and general anesthesia, and 37 % were unaware that driving is permitted after having throat spray alone. The most informed of the age groups had the lowest uptake of sedation and the least informed had the highest uptake.

CONCLUSION

The decision to undergo gastroscopy with or without sedation is not a sufficiently informed one. This study highlights the need for the widespread dissemination of good quality information to inform patients better regarding sedation prior to OGD.

Evaluation of antimicrobial resistance profiles of Salmonella isolates from broiler chickens at slaughter in Alberta, Canada

Antimicrobial-resistant Salmonella species are threatening to become a serious public health problem. Therefore, surveillance and prudent use of antimicrobials is needed in both the agricultural and human health sectors. The aim of this study was to describe the antimicrobial susceptibility profiles of Salmonella isolates recovered from healthy broiler chickens at slaughter from November 2004 to April 2005. Salmonella isolates recovered from 36 broiler flocks in Alberta, Canada, were serotyped and tested for antimicrobial susceptibility against 15 antimicrobials. Of 272 Salmonella isolates tested, 64.0% were resistant to one or more antimicrobials, 10.0% were resistant to three or more antimicrobials, and 1.8% were resistant to five antimicrobials. All isolates were susceptible to amikacin, amoxicillin-clavulanic acid, ceftiofur, cefoxitin, ceftriaxone, ciprofloxacin, and nalidixic acid. The highest prevalence of resistance was to tetracycline (54.8%), followed by streptomycin (24.2%) and sulfisoxazole (8.4%). The most common multiantimicrobial resistance patterns were to streptomycin-tetracycline (24.3%), streptomycin-sulfisoxazole-tetracycline (6.6%), and ampicillin-streptomycin-sulfisoxazole-tetracycline (3.7%). The strongest associations were observed between resistance to kanamycin and tetracycline (odds ratio = 65.7, P = 0.001) and to ampicillin and sulfisoxazole (odds ratio = 62.9, P = 0.001). Salmonella Hadar and Salmonella Heidelberg were the two most common serovars accounting for 40.4 and 13.6% of the total isolates, respectively. Eighty-one percent and 12.7% of Salmonella Hadar isolates and 62.0 and 8.1% of Salmonella Heidelberg isolates were resistant to 1 or more and three or more antimicrobials, respectively. The flock level prevalence of resistance ranged from 5.6% for trimethoprim-sulfamethoxazole to 83.3% for tetracycline. This study provides baseline information on antimicrobial susceptibility of Salmonella isolates of broiler chickens at slaughter in Alberta that can serve as a benchmark for future research.

Familial breast cancer genetic testing in the West of Ireland

AIMS

The majority of hereditary breast and ovarian cancers are associated with highly penetrant mutations in two genes: BRCA 1 and 2. Our aim was to investigate the prevalence and types of BRCA mutations in patients from the West of Ireland.

METHODS

A retrospective cohort study was undertaken that included all patients from the counties, Mayo, Sligo, Galway, Roscommon, and Clare, who were referred to the National Centre for Medical Genetics (NCMG) for testing for mutations in BRCA 1 or 2 between 2000 and 2010. Data including age, symptoms, family history, Manchester score, and test results were recorded and analysed using SPSS.

RESULTS

The NCMG received 380 referrals from the Western seaboard, including 148 for diagnostic testing and 232 for predictive evaluation. Sixty-five patients did not attend for assessment. Two hundred and fifty-six patients fulfilled criteria for genetic counselling, which was accepted by 184, of whom 127 proceeded to testing. Predictive tests were more often declined than diagnostic [41 (46 %) vs. 16 (17 %)]. Ten mutations in BRCA 1 were identified in 20 patients (15 families), including Exon 1-23del (3 families); Exon 14-20del (2 families) and E143X (2 families). Six mutations in BRCA 2 were identified in 15 patients (12 families) including 8525delC (n = 2 families) and 8205-1G>C (n = 3 families). Patients with positive results had significantly higher Manchester scores than those with negative tests [median 25.5 (12-48) vs. 20 (8-37), p = 0.042, Mann-Whitney U test].

CONCLUSION

To identify patients with highly penetrant variants, referrals should be made with strict adherence to guidelines. Counselling should be individualised to counteract intrinsic psychological barriers to testing.

Evaluation of associations between feed withdrawal and other management factors with Salmonella contamination of broiler chickens at slaughter in Alberta

Salmonellosis is one of the most common bacterial foodborne diseases of public health concern in industrialized countries. Poultry products are considered an important source of Salmonella-related foodborne disease in humans. This study was undertaken to evaluate the relationship between various management factors including feed withdrawal and transportation time with Salmonella contamination in crops, ceca, and carcasses of broiler chickens at slaughter in Alberta. Using a two-stage sampling procedure, 30 matched crop and cecal samples before evisceration and an additional 30 neck skin samples after final wash of broiler chickens were collected at slaughter. A questionnaire was administered at the time of sampling to collect information on flock management risk factors. Cecal contents were individually screened with Salmonella-specific real-time PCR to detect positive flocks, and all cecal, crop, and neck skin samples from positive flocks were processed further for Salmonella isolation and characterization. The flock prevalence of Salmonella was 57.1% and within-flock prevalence of Salmonella for positive flocks was 17.2, 8.1, and 53.9% for ceca, crops, and neck skins, respectively. Salmonella Hadar was the most common serovar identified from crops, ceca, and neck skins of broiler chickens tested. Longer transport (P = 0.04 for neck skins) and waiting time in-plant (P = 0.04 for crops, P = 0.03 for ceca) were identified as important risk factors for Salmonella contamination of broiler chickens at slaughter. Salmonella contamination of broiler chickens could potentially be minimized by reducing waiting time in-plant for flocks with longer transport time.

Alcohol, young people and the media: a study of radio output in six radio stations in England

BACKGROUND

This research investigated the representation of alcohol in radio output. The study was prompted by concerns that media output might be part of a developing culture of excessive drinking among young people.

METHODS

Alcohol comments were examined across six radio stations in England. 1200 h of weekend output was screened and the sampling frame included periods when references to alcohol would be expected, such as the Christmas period. Statistical analysis identified the volume and proportion of comments, whereas qualitative analysis explored these in more depth, focusing on the themes and discourses surrounding alcohol talk.

RESULTS

Of 703 alcohol comments identified, 244 involved presenters. The volume of comments about alcohol varied between stations, being lower on BBC than on commercial stations and being influenced by music genre. Seventy-three percent of comments initiated by presenters, compared with 45% of comments from all sources, encouraged drinking. The majority of comments by presenters support drinking in relation to partying and socializing. Alcohol comments seem to create identity for programmes and forge connections between presenters and audiences, although some presenters achieve this without mentioning drinking. The assumption that alcohol is necessary to have a good time is seldom directly challenged.

CONCLUSIONS

While it may be unsurprising that much of this content reflected themes of weekend drinking and partying, the study suggests that alcohol comments play a particular role in marketing and branding of radio output. Comments about alcohol are shaped by broadcasting conventions that make it difficult to challenge discourses surrounding excessive drinking. Further research is needed on the influence that radio output may have on drinking behaviour among young people.

Epithelioid hemangioendothelioma mimicking a nerve sheath tumor clinically and on MR imaging

Epithelioid hemangioendothelioma is a tumor of the soft tissues arising from the vascular endothelium. It is considered an intermediate grade malignancy. A 42-year-old female patient presented with pain and tingling down her right arm and a mass at the right medial upper extremity. MRI revealed an oblong mass along the course of the neurovascular bundle. Given the clinical and MR findings, a nerve sheath tumor was suspected. At surgery, the mass was adherent to both the brachial artery medially and the median nerve posteriorly. Pathology revealed epithelioid hemangioendothelioma. The imaging characteristics of epithelioid hemangioendothelioma on ultrasound, CT, and MRI are reviewed. Epithelioid hemangioendothelioma can mimic a nerve sheath tumor clinically and radiologically and should be considered in the differential diagnosis of tumors involving or adjacent to a neurovascular bundle.

Prolyl-hydroxylase inhibition and HIF activation in osteoblasts promotes an adipocytic phenotype

Bone is a dynamic environment where cells sense and adapt to changes in nutrient and oxygen availability. Conditions associated with hypoxia in bone are also associated with bone loss. In vitro hypoxia (2% oxygen) alters gene expression in osteoblasts and osteocytes and induces cellular changes including the upregulation of hypoxia inducible factor (HIF) levels. Our studies show that osteoblasts respond to hypoxia (2% oxygen) by enhancing expression of genes associated with adipocyte/lipogenesis phenotype (C/EBPbeta, PPARgamma2, and aP2) and by suppressing expression of genes associated with osteoblast differentiation (alkaline phosphatase, AP). Hypoxia increased HIF protein levels, hypoxic response element (HRE) binding, and HRE-reporter activity. We also demonstrate that prolyl-hydroxylases 2 and 3 (PHD2, PHD3), one of the major factors coordinating HIF degradation under normoxic but not hypoxic conditions, are induced in osteoblasts under hypoxic conditions. To further determine the contribution of PHDs and upregulated HIF activity in modulating osteoblast phenotype, we treated osteoblasts with a PHD inhibitor, dimethyloxaloylglycine (DMOG), and maintained cells under normoxic conditions. Similar to hypoxic conditions, HRE reporter activity was increased and adipogenic gene expression was increased while osteoblastic genes were suppressed. Taken together, our findings indicate a role for PHDs and HIFs in the regulation of osteoblast phenotype.

Hepatocyte growth factor (HGF) adsorption kinetics and enhancement of osteoblast differentiation on hydroxyapatite surfaces

Hepatocyte growth factor (HGF) is a growth factor that promotes angiogenesis (tissue vascularization), cell motility, and cell differentiation, making it a potentially beneficial coating for bone implants. However, very little is known about maximizing HGF attachment to surfaces of tissue-engineered scaffolds. Here, we examine methods and kinetics of HGF adsorption onto a dense hydroxyapatite (HA) surface (used in bone implants) and determine the influence of HGF coating on osteoblast phenotype/differentiation. We demonstrate that incubating HA with HGF in solution (and not allowing the solution to dry) resulted in maximal surface adsorption that was not enhanced by extending incubation time beyond 2 days. Daily shaking of the coated HA surface did not remove adsorbed HGF. To further examine the effect of HA on osteoblast phenotype, MC3T3-E1 preosteoblasts were seeded onto HA or HGF-HA surfaces. Gene expression analyses indicate that HGF coating enhanced osteoblast differentiation as demonstrated by increased runx2 (a transcription factor important for osteoblast lineage and differentiation), alkaline phosphatase (marker of mid stage differentiation) and osteocalcin (marker of late stage differentiation) mRNA levels. Taken together, our results demonstrate that HGF can serve as an excellent bone implant coating based on its ability to readily adsorb to HA surfaces, maintain integrity over time, and enhance osteoblast differentiation.

Reflections on uncertainty in risk assessment and risk management by the Society of Environmental Toxicology and Chemistry (SETAC) precautionary principle workgroup

Quantitative uncertainty assessments and the distribution of risk are under scrutiny and significant criticism has been made of null hypothesis testing when careful consideration of Type I (false positive) and II (false negative) error rates have not been taken into account. An alternative method, equivalence testing, is discussed yielding more transparency and potentially more precaution in the quantifiable uncertainty assessments. With thousands of chemicals needing regulation in the near future and low public trust in the regulatory process, decision models are required with transparency and learning processes to manage this task. Adaptive, iterative, and learning decision making tools and processes can help decision makers evaluate the significance of Type I or Type II errors on decision alternatives and can reduce the risk of committing Type III errors (accurate answers to the wrong questions). Simplistic cost-benefit based decision-making tools do not incorporate the complex interconnectedness characterizing environmental risks, nor do they enhance learning, participation, or include social values and ambiguity. Hence, better decision-making tools are required, and MIRA is an attempt to include some of the critical aspects.

Subcutaneous emphysema of the neck and colonic perforation

Subcutaneous emphysema may result from pathological changes in the thorax or lung, as a result of localised infection with gas producing organisms, after abdominal procedures, or herald an intestinal perforation. The location and spread of extraperitoneal gas is determined by the anatomical barriers and fixed fascial layers surrounding the region of pathological change. The case highlights the extent of extraperitoneal gas after colonic perforation despite minimal clinical features and the importance of intra-abdominal causes of cervical subcutaneous emphysema.

Parathyroid hormone stimulates fra-2 expression in osteoblastic cells in vitro and in vivo

PTH and PTH-related protein (PTHrP) are key mediators of skeletal development and homeostasis through their activation of the PTH-1 receptor. Previous studies have found that several AP-1 family members are regulated by PTH, such as c-fos, fra-1, and c-jun. There are numerous genes in the bone microenvironment that contain AP-1 sites, and different Fos family members are reported to have opposing transcriptional activities at AP-1 sites. The purpose of this study was to identify the effects of PTH on expression of the AP-1 protein complex member, fra-2, to extend our understanding of transcriptional regulators of PTH action. PTH induction of fra-2 messenger RNA (mRNA) levels in MC3T3-E1 preosteoblastic cells was maximal with 0.1 microM PTH (1-34). The expression in vitro was greatest 1 h after treatment and was present with N-terminal PTH but not PTH (7-34) or (53-84). Cycloheximide treatment induced fra-2 expression, and actinomycin D inhibited basal and PTHrP-induced expression. AP-1 protein in nuclear extracts of MC3T3-E1 cells was increased with PTH treatment at 3 h and consisted of high levels of Fra-2 protein, as evidenced by a supershift in an electrophoretic mobility shift assay and Western blot analysis. Up-regulation of steady-state fra-2 mRNA was also noted in vivo, where injection of PTH (1-34) (20 microgram) resulted in a more-than-7-fold maximal increase in fra-2 mRNA expression in the calvaria of mice, after 1 h of treatment. These data add to the transcriptional mediators induced by PTH and suggest that the interplay of AP-1 family members will provide insight into regulatory pathways of PTH and PTHrP for their anabolic and catabolic actions in bone.

Lecture 5: erectile dysfunction in the HIV-positive male: a review of medical, legal and ethical considerations in the age of oral pharmacotherapy

Urologists and health care professionals treating erectile dysfunction face a significant challenge in caring for the HIV-positive patient who seeks restoration of normal sexual function. The encounter between the health care provider and the patient in this setting requires knowledge of HIV disease and potential drug interactions specific to this population, as well as thorough counseling on strategies aimed at reducing the infectiousness of HIV-1. The interaction extends beyond the immediate boundaries of the doctor-patient relationship and their respective rights, to include careful consideration of the rights of the partner/s and the society as a whole. This paper is a summary and analysis of presentations and discussions by medical, legal, nursing and bioethics specialists in an interactive seminar on this topic.

Extracellular glucose influences osteoblast differentiation and c-Jun expression

Insulin dependent diabetes mellitus, marked by high blood glucose levels and no insulin secretion, is associated with decreased bone mass and increased fracture rates. Analysis of bone histology suggests that osteoblast phenotype and function are influenced by diabetes. To determine if elevated extracellular glucose levels could directly influence osteoblast phenotype we treated mouse osteoblasts, MC3T3-E1 cells, with 22 mM glucose and analyzed osteoblast gene expression. Collagen I mRNA levels significantly increased while osteocalcin mRNA levels decreased 24 h after the addition of glucose. Expression of other genes, actin, osteopontin, and histone H4, was unaffected. Effects on collagen I expression were seen as early as 1 h after treatment. c-Jun, an AP-1 transcription factor involved in the regulation of osteoblast gene expression and growth, was also modulated by glucose. Specifically, an increase in c-jun expression was found at 1 h and maintained for 24 h following glucose treatment. Treatment of osteoblasts with an equal concentration of mannitol completely mimicked glucose treatment effects on collagen I and c-jun expression, demonstrating that osmotic stress rather than glucose metabolism is responsible for the effects on osteoblast gene expression and phenotype. Additional studies using staurosporine and Ro-31-8220 demonstrate that protein kinase C is required for the glucose up regulation of collagen I and c-jun. Taken together, our results demonstrate that osteoblasts respond to increasing extracellular glucose concentration through an osmotic response pathway that is dependent upon protein kinase C activity and results in upregulation of c-jun and modulation of collagen I and osteocalcin expression.

Bacteriological and histological profile of turkeys condemned for cyanosis

Canadian Food Inspection Agency (CFIA) has adopted the term cyanosis to describe a category of condemnation for poultry that is dark but has no other condemnable lesions. Two case-control studies (n = 30 pairs; n = 65 pairs) of 18-wk-old tom turkeys were conducted. A case was defined as a carcass condemned by the veterinary inspector for cyanosis, and a control carcass was one that passed inspection. Microbiological tests were conducted on samples of Pectoralis major and Gastrocnemius lacteralis. A modified Rappaport Vassiliadis medium was used for Salmonella, and a Petrifilm method was used to assess aerobic counts, coliform counts, and Escherichia coli. The Salmonella (qualitative) test was negative for all cases and controls, and there were no significant differences between the aerobic counts, coliform counts, and E. coli counts of case and control carcasses. Two pathologists conducted a blind histopathological study: there were no lesions compatible with those of septicemia-toxemia, as defined by CFIA and the USDA, nor any significant histopathological differences between the skin, P. major, G. lateralis, kidney, liver, spleen, small intestine, pancreas, lung, and heart of cases and controls. The inter-rater agreement between pathologists ranged from good to excellent (Kappa = 0.7 to 1.0). In the absence of important lesions and microbial contamination, carcasses with this color change alone should be suitable for human consumption.

Treatments for patients with sexual problems

Nurses need to be aware of psychosexual issues in patient care. If necessary, nurses must be able to direct the patient to sources of specialist help. Sex therapy and psychosexual medicine both offer approaches to sexual dysfunction.

The work of clinical nurse specialists (HIV/AIDS) in areas with a low prevalence of HIV infection

The role of the clinical nurse specialists (HIV/AIDS) who work in areas with a low known prevalence of HIV is considered and their contribution to patient care, either directly or indirectly through the education and support of other health care workers, is discussed. Attention is given to the implications for nursing practice and the role of the clinical nurse specialist associated with the relative infrequency of contact with patients who have HIV disease; and some of the issues for people living with HIV/AIDS in rural areas are alluded to. Finally, some of the limitations of the clinical nurse specialist role are delineated and some consideration is given to the future role of clinical nurse specialists for HIV and AIDS.

Psychosis following acute alteration of thyroid status

OBJECTIVE

Mania with psychotic features presenting following abrupt normalisation of thyroid function from severe Graves's disease is reported.

CLINICAL PICTURE

A 33-year-old man with severe, untreated Graves's disease was treated aggressively, with rapid restoration of normal serum thyroid hormone levels. Symptoms of mania and psychosis then developed.

TREATMENT

Time limited antipsychotic medication and continuing medical treatment.

OUTCOME

There was resolution of psychiatric symptoms.

CONCLUSIONS

The association of mania and psychosis with thyroid disease is rare, but aggressive medical treatment and rapid restoration of normal serum thyroid levels may increase the risk of the emergence of such symptoms.

Gradient-echo perfusion imaging of musculoskeletal abnormalities with contrast-enhanced two-dimensional fat-saturation FLASH

The objective of this study was to evaluate the utility of MR perfusion imaging of various musculoskeletal lesions with a contrast-enhanced two-dimensional fat saturation fast low angle shot (FLASH) sequence and to assess the potential of this technique for distinguishing malignant from benign conditions. Thirty-six musculoskeletal lesions were studied at 1.5 T. The signal intensity of the lesions, adjacent artery, muscle, bone marrow, and fat were plotted against time. The time to peak enhancement, time to maximum signal intensity, percent enhancement, rate of peak enhancement, and rate of enhancement parameters were calculated. Because of a significant overlap between malignant and benign conditions, accuracy rates were lower than reported previously. The best parameter based on these values was the rate of peak enhancement (sensitivity, 84.6%; specificity, 65.2-66.6%; positive predictive value, 57.8-68.7%). Fat saturation gradient-echo MR perfusion imaging allows for a rapid assessment of the vascularity of musculoskeletal pathology; however, a significant overlap persists between malignant neoplasms and several benign conditions.

Prevention of rhinovirus infection in chimpanzees by soluble intercellular adhesion molecule-1

Intercellular adhesion molecule-1 (ICAM-1) is the cell surface receptor for the major class of human rhinoviruses, and tICAM453, a truncated, soluble form of ICAM-1, has been shown previously to be a potent in vitro inhibitor of rhinovirus. In this report, we have investigated the in vivo efficacy of tICAM453 for the prophylaxis of rhinovirus serotype 16 infection in the chimpanzee. Because chimpanzees do not show clinical symptoms of infection after rhinovirus challenge, infection was followed by measuring antirhinovirus serum antibody responses and detection of virus shedding. By both of these measures, intranasal application of tICAM453 was efficacious in preventing rhinovirus infection in chimpanzees subsequently challenged with infectious doses of virus. These results suggest that the use of soluble rhinovirus receptor to inhibit virus binding to host cells should be feasible in humans.

Sexual health promotion and nursing

The HIV epidemic provides continued impetus for effective sexual health promotion. Sexual health promotion in nursing practice has traditionally been equated to prevention at primary, secondary and tertiary levels. Increasing demands on practitioners to address the psycho-social aspects of sexual health, together with a greater emphasis on primary prevention, is leading to the adoption of theoretical paradigms from the behavioural sciences and the increasing use of counselling skills. The limitations of individualist interventions for primary prevention are explored, and the assumption that health care professionals are effective promoters of sexual health is questioned. The importance of placing sexual health and nursing practice within a wider social, political and cultural context is emphasized.

Posterior urethral diverticulum presenting as a midline prostatic cyst: sonographic and MRI appearance

A midline cystic structure in the prostate most commonly represents a Mullerian duct cyst or dilated utricle. We describe the sonographic and magnetic resonance imaging (MRI) appearance of a rare diverticulum of the posterior urethra presenting as a midline prostatic cyst.

Effects of modulators of the renin-angiotensin-aldosterone system on cough. Losartan Cough Study Group

OBJECTIVE

To compare the incidence of cough in patients with a history of angiotensin converting enzyme (ACE) inhibitor-related cough who received losartan [a type 1 angiotensin II (Ang II) receptor antagonist], lisinopril (an ACE inhibitor) or hydrochlorothiazide (a diuretic).

DESIGN

An international, multicentre, randomized double-blind, parallel-group controlled trial.

SETTING

Outpatient clinics at 20 tertiary care medical centres in 11 countries.

PATIENTS

One hundred and thirty-five patients with uncomplicated primary hypertension with a history of ACE inhibitor-related cough were randomly assigned to the double-blind treatment phase and completed the study.

INTERVENTION

After confirming that the cough was ACE inhibitor-related by a single-blind rechallenge, followed by a placebo washout period, patients were randomly assigned to receive 50mg losartan, 20mg lisinopril or 25mg hydrochlorothiazide once a day for 8 weeks.

MAIN OUTCOME MEASURES

Cough incidence, severity and frequency were assessed by a self-administered questionnaire and a visual analogue scale.

RESULTS

The percentage of patients who complained of cough was significantly higher with lisinopril than with losartan or hydrochlorothiazide. The mean visual analogue scale scores for patients treated with lisinopril demonstrated that these patients coughed more frequently than those who received losartan or hydrochlorothiazide.

CONCLUSION

The incidence of cough related to the type 1 Ang II receptor antagonist losartan is significantly lower than that observed with lisinopril, and similar to that observed with hydrochlorothiazide in patients with a rechallenged ACE inhibitor cough. Type 1 Ang II receptor antagonists represent a potential new treatment for hypertensive patients in whom ACE inhibitors are indicated, but who develop a cough with these agents.

Toxicokinetics of pentachloroanisole in F344 rats and B6C3F1 mice

1. Toxicokinetics of pentachloroanisole (PCA) were studied in F344 rat and B6C3F1 mouse of both sexes by gavage at doses of 10, 20 and 40 mg/kg and by i.v. at 10 mg/kg. 2. PCA was rapidly demethylated to pentachlorophenol (PCP) in both rat and mouse and the resulting PCP plasma concentrations were much higher than that of parent PCA due to the much smaller apparent volume of distribution of PCP. 3. Peak plasma concentrations of PCA and PCP increased with dose in both rat and mouse. 4. Bioavailability of PCA was low in both rat and mouse and was sex independent. 5. The high plasma concentrations and relatively long biological half-life of PCP in both species after both i.v. and oral dosing with PCA indicate possible bioaccumulation of PCP upon multiple oral administrations of PCA.

NTP technical report on the toxicity studies of Castor Oil (CAS No. 8001-79-4) in F344/N Rats and B6C3F1 Mice (Dosed Feed Studies)

Castor oil is a natural oil derived from the seeds of the castor bean, Ricinus communis. It is comprised largely of triglycerides with a high ricinolin content. Toxicity studies with castor oil were performed by incorporating the material at concentrations as high as 10% in diets given to F344/N rats and B6C3F1 mice of both sexes for 13 weeks. Genetic toxicity studies also were performed and were negative for mutation induction in Salmonella typhimurium, for induction of sister chromatid exchanges or chromosomal aberrations in Chinese hamster ovary cells, and for induction of micronuclei in the peripheral blood erythrocytes of mice evaluated at the end of the 13-week studies. Exposure to castor oil at dietary concentrations as high as 10% in 13-week studies did not affect survival or body weight gains of rats or mice (10 per sex and dose). There were no biologically significant effects noted in hematologic analyses in rats. Mild increases in total bile acids and in serum alkaline phosphatase were noted at various times during the studies in rats receiving the higher dietary concentrations of castor oil. Liver weights were increased in male rats receiving the 10% dietary concentration and in male and female mice receiving diets containing 5% or 10% castor oil. However, there were no histopathologic lesions associated with these liver changes, nor were there any compound-related morphologic changes in any organ in rats or mice. No significant changes were noted in a screening for male reproductive endpoints, including sperm count and motility, and no changes were observed in the length of estrous cycles of rats or mice given diets containing castor oil. Thus, no significant adverse effects of castor oil administration were noted in these studies. Synonyms: Ricinus Oil, oil of Palma Christi, tangantangan oil, phorboyl, Neoloid.

Identifiable semen donors--attitudes of donors and recipient couples

Fifty-three couples embarking on donor insemination (DI) replied to an anonymous questionnaire asking what they wanted to know about the donor should they become pregnant. Fifty-one percent were definitely and 32% probably going to tell a child of its donor origins. Items most frequently listed for themselves and on behalf of a child were--interests/sports (57%), physical attributes (41%), occupation (37%) and family background (26%). Forty-two percent of the women and 28% of the men thought the child should have access to the identity of the donor eventually. Thirty-eight donors were surveyed by a questionnaire; 68% were agreeable to their identity being available to a donor insemination child when the child reached maturity. When the category of identifiable donor was created, 20 of 36 (56%) new donors and donors still donating chose this option.

Efficacy of ticarcillin-clavulanic acid for treatment of experimental Staphylococcus aureus endocarditis in rats

The efficacy of ticarcillin-clavulanic acid was compared with the efficacies of standard antistaphylococcal agents (flucloxacillin, oxacillin, nafcillin, and vancomycin) and ticarcillin in an experimental model of Staphylococcus aureus endocarditis. Therapy was either initiated soon (8 h) after infection, when numbers of bacteria in aortic valve vegetations were relatively low (approximately 6 to 8 log10 CFU/g), or delayed until 24 h after infection, when the vegetations usually contained greater than 9 log10 CFU/g. Doses of the antibiotic were selected to produce peak concentrations in rat serum similar to those achievable in humans after administration of parenteral therapeutic doses. Ticarcillin-clavulanic acid was more effective overall than ticarcillin alone against endocarditis caused by beta-lactamase-producing strains of S. aureus, illustrating the beta-lactamase-inhibitory activity of clavulanic acid in vivo. Ticarcillin-clavulanic acid was as effective as the standard antistaphylococcal beta-lactam agents flucloxacillin, oxacillin, and nafcillin in these infections, whereas vancomycin was generally less active. These results illustrate the clinical potential of ticarcillin-clavulanic acid in the prophylaxis or therapy of severe staphylococcal infections.

Efficacy of amoxycillin/clavulanic acid in experimental Staphylococcus aureus endocarditis in the rat

The efficacy of amoxycillin/clavulanic acid was compared with that of flucloxacillin, vancomycin and amoxycillin in an experimental model of Staphylococcus aureus endocarditis. Doses of the antibiotics were selected to produce peak concentrations in rat serum similar to those achievable in man after administration of parenteral therapeutic doses. Amoxycillin clavulanic acid was more effective than amoxycillin alone against endocarditis caused by beta-lactamase producing strains of Staph. aureus, illustrating the beta-lactamase inhibitory activity of clavulanic acid in vivo. Amoxycillin/clavulanic acid was as effective as flucloxacillin in these infections whereas vancomycin was generally less active. These results illustrate the clinical potential of amoxycillin/clavulanic acid in the prophylaxis, or in the therapy of severe staphylococcal infections.